Christchurch brewer Hamish Jones has a love-hate affair with chestnuts.
The award-winner has spent the last five years perfecting the recipe for a gluten-free chestnut lager that's now sold in supermarkets all over the country. The concoction is 60 percent chestnuts, replacing traditional barley and inviting all sorts of logistical problems.
"If I didn't like a challenge, and wasn't so stupid, I probably would have walked away," Mr Jones says.
"To do it again, I'd probably run. It's not cheap, it's not easy to use, you don't get very good sugar conversation out of it, so you've got to use another couple of subtle ingredients."
The brewer, who reckons he's the first person in the country to pull the beer off, stumbled on the idea online after "a few beers". He knew he was on to a winner when a cousin, now a shareholder, drank four jugs in the first sitting.
"It's more a cider, ginger beer taste than a traditional beer just because most coeliacs and gluten intolerant people haven't been drinking anything other than wine or cider," he says.
"It's kind of a gateway beer, so they can taste it, drink it, get back into it, and once they've done that we'll get them hooked on the 2 percent pale ale and 5 percent pale ale we're doing at the moment."
Mr Jones had to build his own small plant to create the beer to avoid gluten contamination at the large breweries on offer around town. The 4 percent 'Cheslic' brand is selling for $5.50 a bottle in New World and Fresh Choice supermarkets at Auckland, Wellington and across the South Island.
He won't reveal the exact formula for the brew but says others, including a team at Massey University, have attempted to the make the chestnut beer and failed when discovering the cost. Where most brewers pay $1.40 a kilo for malted barley, Mr Jones is paying $7.
The brewer is now working on another top-secret project - gluten-free chestnut-based whiskey.